1 /* $OpenBSD: dead_vnops.c,v 1.14 2003/06/02 23:28:10 millert Exp $ */ 2 /* $NetBSD: dead_vnops.c,v 1.16 1996/02/13 13:12:48 mycroft Exp $ */ 3 4 /* 5 * Copyright (c) 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)dead_vnops.c 8.2 (Berkeley) 11/21/94 33 */ 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/time.h> 38 #include <sys/vnode.h> 39 #include <sys/errno.h> 40 #include <sys/namei.h> 41 #include <sys/buf.h> 42 #include <sys/proc.h> 43 44 /* 45 * Prototypes for dead operations on vnodes. 46 */ 47 int dead_badop(void *); 48 int dead_ebadf(void *); 49 50 int dead_lookup(void *); 51 #define dead_create dead_badop 52 #define dead_mknod dead_badop 53 int dead_open(void *); 54 #define dead_close nullop 55 #define dead_access dead_ebadf 56 #define dead_getattr dead_ebadf 57 #define dead_setattr dead_ebadf 58 int dead_read(void *); 59 int dead_write(void *); 60 int dead_ioctl(void *); 61 int dead_select(void *); 62 #define dead_fsync nullop 63 #define dead_remove dead_badop 64 #define dead_link dead_badop 65 #define dead_rename dead_badop 66 #define dead_mkdir dead_badop 67 #define dead_rmdir dead_badop 68 #define dead_symlink dead_badop 69 #define dead_readdir dead_ebadf 70 #define dead_readlink dead_ebadf 71 #define dead_abortop dead_badop 72 #define dead_inactive nullop 73 #define dead_reclaim nullop 74 int dead_lock(void *); 75 #define dead_unlock vop_generic_unlock 76 int dead_bmap(void *); 77 int dead_strategy(void *); 78 int dead_print(void *); 79 #define dead_islocked vop_generic_islocked 80 #define dead_pathconf dead_ebadf 81 #define dead_advlock dead_ebadf 82 #define dead_bwrite nullop 83 84 int chkvnlock(struct vnode *); 85 86 int (**dead_vnodeop_p)(void *); 87 88 struct vnodeopv_entry_desc dead_vnodeop_entries[] = { 89 { &vop_default_desc, vn_default_error }, 90 { &vop_lookup_desc, dead_lookup }, /* lookup */ 91 { &vop_create_desc, dead_create }, /* create */ 92 { &vop_mknod_desc, dead_mknod }, /* mknod */ 93 { &vop_open_desc, dead_open }, /* open */ 94 { &vop_close_desc, dead_close }, /* close */ 95 { &vop_access_desc, dead_access }, /* access */ 96 { &vop_getattr_desc, dead_getattr }, /* getattr */ 97 { &vop_setattr_desc, dead_setattr }, /* setattr */ 98 { &vop_read_desc, dead_read }, /* read */ 99 { &vop_write_desc, dead_write }, /* write */ 100 { &vop_ioctl_desc, dead_ioctl }, /* ioctl */ 101 { &vop_select_desc, dead_select }, /* select */ 102 { &vop_fsync_desc, dead_fsync }, /* fsync */ 103 { &vop_remove_desc, dead_remove }, /* remove */ 104 { &vop_link_desc, dead_link }, /* link */ 105 { &vop_rename_desc, dead_rename }, /* rename */ 106 { &vop_mkdir_desc, dead_mkdir }, /* mkdir */ 107 { &vop_rmdir_desc, dead_rmdir }, /* rmdir */ 108 { &vop_symlink_desc, dead_symlink }, /* symlink */ 109 { &vop_readdir_desc, dead_readdir }, /* readdir */ 110 { &vop_readlink_desc, dead_readlink }, /* readlink */ 111 { &vop_abortop_desc, dead_abortop }, /* abortop */ 112 { &vop_inactive_desc, dead_inactive }, /* inactive */ 113 { &vop_reclaim_desc, dead_reclaim }, /* reclaim */ 114 { &vop_lock_desc, dead_lock }, /* lock */ 115 { &vop_unlock_desc, dead_unlock }, /* unlock */ 116 { &vop_bmap_desc, dead_bmap }, /* bmap */ 117 { &vop_strategy_desc, dead_strategy }, /* strategy */ 118 { &vop_print_desc, dead_print }, /* print */ 119 { &vop_islocked_desc, dead_islocked }, /* islocked */ 120 { &vop_pathconf_desc, dead_pathconf }, /* pathconf */ 121 { &vop_advlock_desc, dead_advlock }, /* advlock */ 122 { &vop_bwrite_desc, dead_bwrite }, /* bwrite */ 123 { (struct vnodeop_desc*)NULL, (int(*)(void *))NULL } 124 }; 125 struct vnodeopv_desc dead_vnodeop_opv_desc = 126 { &dead_vnodeop_p, dead_vnodeop_entries }; 127 128 /* 129 * Trivial lookup routine that always fails. 130 */ 131 /* ARGSUSED */ 132 int 133 dead_lookup(v) 134 void *v; 135 { 136 struct vop_lookup_args /* { 137 struct vnode * a_dvp; 138 struct vnode ** a_vpp; 139 struct componentname * a_cnp; 140 } */ *ap = v; 141 142 *ap->a_vpp = NULL; 143 return (ENOTDIR); 144 } 145 146 /* 147 * Open always fails as if device did not exist. 148 */ 149 /* ARGSUSED */ 150 int 151 dead_open(v) 152 void *v; 153 { 154 155 return (ENXIO); 156 } 157 158 /* 159 * Vnode op for read 160 */ 161 /* ARGSUSED */ 162 int 163 dead_read(v) 164 void *v; 165 { 166 struct vop_read_args /* { 167 struct vnode *a_vp; 168 struct uio *a_uio; 169 int a_ioflag; 170 struct ucred *a_cred; 171 } */ *ap = v; 172 173 if (chkvnlock(ap->a_vp)) 174 panic("dead_read: lock"); 175 /* 176 * Return EOF for tty devices, EIO for others 177 */ 178 if ((ap->a_vp->v_flag & VISTTY) == 0) 179 return (EIO); 180 return (0); 181 } 182 183 /* 184 * Vnode op for write 185 */ 186 /* ARGSUSED */ 187 int 188 dead_write(v) 189 void *v; 190 { 191 struct vop_write_args /* { 192 struct vnode *a_vp; 193 struct uio *a_uio; 194 int a_ioflag; 195 struct ucred *a_cred; 196 } */ *ap = v; 197 198 if (chkvnlock(ap->a_vp)) 199 panic("dead_write: lock"); 200 return (EIO); 201 } 202 203 /* 204 * Device ioctl operation. 205 */ 206 /* ARGSUSED */ 207 int 208 dead_ioctl(v) 209 void *v; 210 { 211 struct vop_ioctl_args /* { 212 struct vnode *a_vp; 213 u_long a_command; 214 caddr_t a_data; 215 int a_fflag; 216 struct ucred *a_cred; 217 struct proc *a_p; 218 } */ *ap = v; 219 220 if (!chkvnlock(ap->a_vp)) 221 return (EBADF); 222 return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap)); 223 } 224 225 /* ARGSUSED */ 226 int 227 dead_select(v) 228 void *v; 229 { 230 /* 231 * Let the user find out that the descriptor is gone. 232 */ 233 return (1); 234 } 235 236 /* 237 * Just call the device strategy routine 238 */ 239 int 240 dead_strategy(v) 241 void *v; 242 { 243 244 struct vop_strategy_args /* { 245 struct buf *a_bp; 246 } */ *ap = v; 247 int s; 248 249 if (ap->a_bp->b_vp == NULL || !chkvnlock(ap->a_bp->b_vp)) { 250 ap->a_bp->b_flags |= B_ERROR; 251 s = splbio(); 252 biodone(ap->a_bp); 253 splx(s); 254 return (EIO); 255 } 256 return (VOP_STRATEGY(ap->a_bp)); 257 } 258 259 /* 260 * Wait until the vnode has finished changing state. 261 */ 262 int 263 dead_lock(v) 264 void *v; 265 { 266 struct vop_lock_args /* { 267 struct vnode *a_vp; 268 int a_flags; 269 struct proc *a_p; 270 } */ *ap = v; 271 struct vnode *vp = ap->a_vp; 272 273 /* 274 * Since we are not using the lock manager, we must clear 275 * the interlock here. 276 */ 277 if (ap->a_flags & LK_INTERLOCK) { 278 simple_unlock(&vp->v_interlock); 279 ap->a_flags &= ~LK_INTERLOCK; 280 } 281 if (ap->a_flags & LK_DRAIN || !chkvnlock(vp)) 282 return (0); 283 284 return (VCALL(vp, VOFFSET(vop_lock), ap)); 285 } 286 287 /* 288 * Wait until the vnode has finished changing state. 289 */ 290 int 291 dead_bmap(v) 292 void *v; 293 { 294 struct vop_bmap_args /* { 295 struct vnode *a_vp; 296 daddr_t a_bn; 297 struct vnode **a_vpp; 298 daddr_t *a_bnp; 299 int *a_runp; 300 } */ *ap = v; 301 302 if (!chkvnlock(ap->a_vp)) 303 return (EIO); 304 return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp)); 305 } 306 307 /* 308 * Print out the contents of a dead vnode. 309 */ 310 /* ARGSUSED */ 311 int 312 dead_print(v) 313 void *v; 314 { 315 printf("tag VT_NON, dead vnode\n"); 316 return 0; 317 } 318 319 /* 320 * Empty vnode failed operation 321 */ 322 /*ARGSUSED*/ 323 int 324 dead_ebadf(v) 325 void *v; 326 { 327 328 return (EBADF); 329 } 330 331 /* 332 * Empty vnode bad operation 333 */ 334 /*ARGSUSED*/ 335 int 336 dead_badop(v) 337 void *v; 338 { 339 340 panic("dead_badop called"); 341 /* NOTREACHED */ 342 } 343 344 /* 345 * We have to wait during times when the vnode is 346 * in a state of change. 347 */ 348 int 349 chkvnlock(vp) 350 register struct vnode *vp; 351 { 352 int locked = 0; 353 354 while (vp->v_flag & VXLOCK) { 355 vp->v_flag |= VXWANT; 356 tsleep(vp, PINOD, "chkvnlock", 0); 357 locked = 1; 358 } 359 return (locked); 360 } 361